Process for wireless telegraphy and telephony



July 17, '1928. 1,677,296

B. 'ROSENBAUM PRGCESS FOR WIRELESS TELEGRAPHY AHD TELEPHONY Filed Aug. 26. 1921 400 44 4/ /'0 o o g 0 (02 v 700 45 o o I I 0 o 46" o 9; 4? o o Y WITNESSES: INVENTOR W 5/0/70 Fosenaum Patented July 17, 1928.

UNITED STATES PATENT OFFICE.

BRUNO ROSENBAUM. OF BERLIN, GERMANY, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

PROCESS FOR WIRELESS TELEGRAPHY AND TELEPHONY.

Application filed August 26, 1921, Serial No. 495,742, and in Germany August 18, 1917.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT. L., 1313.)

lhis invention relates to wireless signals. An object of this invention is to provide a means for signalling to a, remote station without using such intense signals that they will be received at other remote stations.

It is a further object of this invention to provide a chain of intermediate stations each receiving the signal from the preceding station and delivering it to the succeeding station. I I

It is a further object of this invention to provide means for automatically causing each intermediate station to change from receiving to sending arrangement upon the completion of the reception of the message;

It is a further object of this invention cause each intermediate station to automatically send the message to the next station as soon as the reception of the message from the preceding station is completed.

It is a further object of this invention to prevent the radiations from any intermediate station from affecting the apparatus in the preceding station.

It is a further object of this invention to provide a switch-controlling device, responsive to a predetermined sequence of signals, by means of which change from the wwwmg to sending arrangement may be made at any intermediate station upon the arrival of such signals from the preceding station. The means for accomplishing this change can also be used for changing the arrangement back again when the intermediate station delivers the predetermined sequence of signals to the succeeding station.

It is a further object of this invention to provide automatic recording and transmitting means at each station which shall Work rapidly enough to enable a large number tails of the construction will be apparent from the following description and the accompanying drawings in which:

'Figurel is a diagrammatic indication of a chain of stations, I

Fig. 2 is a diagram of the arrangement of apparatus and connections at an intermediate station,

-Fig. 3 is a diagram of the sending apparatus at a central station, and

Fig. 4 is a diagram illustrating an arrangement of several chains of stations about one central station.

In Figure 1, 3 represents the end station at the beginning of the chain. The intermediate stations are represented at 4, 5, 6, 7, 8, 9 and 10. The curved dotted lines in this figure represent the radiations from each station. Outside of the two parallel dotted lines. the radiations become too feeble to affect stations which do not belong to the chain and are not located between said lines. Thus, the radiations sent out from the station 3 reach the station 4 but do not reach station 5 with sufficient strength to aii ect the apparatus there. The apparatus at station 4, in its turn, sends out radiations which will be cilective at the station 5. These radia tions are prevented from producing a result at station 3, by means which will be explained below. In the same way, the radiations from station 5 produce a result at sta tion 6 but not at station 4. They are too feeble toproduec any result at stations 7 or 3 or at stations at one side of the chain more remote than the parallel dotted lines. In this way, the message started at station 3 isreceived at the station 4, where it is repeated and received at the station 5, where it is again repeated andreceived at the station 6 and so on until it reaches the final station.

It will be obvious that the intensity of the signals sent out from the station 3 does not need to be great enough'to affect the instruments at station 10, consequently, the danger of signals from station 3 being received at remote statlons, where it is undesirable to have them known, is avoided. Secrecy is represented in Figure 3, includes a microphone 11 or other device for controlling the signal. It also has a sending device 12 which delivers energy to the antenna 13. If desired, the sending device 12 may include an arrangement, similar to that described below in connection with the Fig. 2, for delivering the message to the antenna 13 at a much greater speed than that at which the operator speaks into the'microphone 11.

Themessage sent out from the antenna 13 of station is received upon the antenna 1 1 atstation 41., shown in Fig. 2. This station will, at this time, have the switches 15 and 15A in the left-hand position, so that the connection from the antenna to the ground includes the receiver 16. The message deliv ered'from station 3 is thus received at station 4 and recorded by the receiving instrument upon the traveling steel band 17. In position to be affected by the moving magnetized band 17 are three coils 18A, 18B and 18C, associated respectively with three relays 19A, 19B and 19C to form resonance relays, so tuned that they act successively when appropriate signals. are sent in succession. When the operator at station 12-) has completed a message, he sends a signal which consists of the three trequenciesto which these relays can respond. These frequencies are sent in a predetermined' sequence. They may be sent by sounding a trumpet into .the micro" phone 11 so as to give the needed sequence: of notes, or a. chime of properly tuned bells may be rung in proximity to the microphone. Any other device which produces sustained notes in proper order could be used.

In the form of: the apparatus chosen for illustration, this sequence is such that the relay 19A is first operated, the relay 1913 next, and the relay 19C last. Three relays 20A, 20B and'2OC are so arranged that, if the relays 19A, 19B and 19C are'ene-rgized in the sequence named, the relay 20A will cause a change in the position of the switches 15' and 15A, but otherwise not. The network of connections by which the relays 19A, 19B and 19C accomplish this selective response forms no part'oi' my invention. Any set of relays which will respond only to the predetermined sequence may be used. For the sake of clearness, however, I have illustrated in detail a network which will produce this result. In it, the relay 20A is slower than the relay 20B and the relay 20C is faster than the relay 20B. WVhen the relay 19A is energized, it causes the relay 20A to close its contacts. This establishes-a holding circuit for the relay 20A, which .will be opened whenever the relay 1913 or 19C is energized. If,

after the relay 19A has been energized, the

relay 19B becomes energized, it closes the circuit through the relay 2013. This circuit is opened by the deenergization of the relay 20A, which begins at once but is not accomra'tus at the station 5.

plished until the relay 2013 has had time to close its contacts. The relay 20B is then kept energized by a holding circuit which is controlled by thev relays 19A and 190. In the same way, energization of the relay 1 96, after relays 19A and 1913 have been energized in iurn, will result in energization of the relay 2OC.

The relay 20C is to move the switches 15 and 15A lirst in one direction and then in. the other. This may be accomplished in any desired way. For the sake of a clear illustration, one way has been shown in detail, but none or the details constitute part of the invention. In the illustrated form, the

relay 20C operates a ratchet-wheel 31, theteeth of which are alternately high and low. A high tooth, contacting with the roller 32, will close a. circuit through magnets 33 and 34:. er, this circuit will be opened. With the apparatus in the illustrated position, the mag nets 33 and 3/1 are energized, and, consequently, the switches and 15A are in the lett-hand position. This 'is the position which the switches occupy while station 4-. is receiving the message trom station 3. At

the end of the message, the predetermined sequence of special iii'quencies is sent, which,

causes the relay C to step the ratchet-wheel 31 one notch. This opens the circuit through the magnets 33 and and so causes the switches 15 and 15Ato take the opposite po- Sit L011. 1

At the sametime that the magnets 33 and 34 are deenergized, the magnet rcleasesits armature, to cause the coil 21 to be operativelyv connected. with the amplifier 22. Although I have illustrated a relay controlling theconnection of coil 21 to the amplifier, this 'teature of my invention comprises anymeans supplementing the switches 15 and 15A for rendering the transmitter active only when these are on contacts 20 and 20A respectively. As the wire 17, upon which the message has been magnetically recorded, passes the coil 21, the impulses generated in said coil are amplified by the amplifier 22 and impressed upon the grid of the generator tube 23.. The output circuit of this tube is supplied by the battery 25 and includes a coil 26 and a condenser 27 inv parallel. This circuit isfconnected, byaneans of the switches 15-and 15A, to the antenna 14. Consequently, the antenna 14: willsend radiations, modulated in accord'ance with the impulses im pressed upon the coil 21, and will, therefore, deliver the message which was recorded upon the" wire 17. The message thus delivered is impressed upon the receiving appa- In order that it shall not at the same time be impressed at station 3, the. radiations which station t sends must be of a different wave length from those used. When station t is receiving. This W hen a low tooth contacts wit-h the roll-- Ill" change of wavelength may be accomplished by having the switch 15 remove a portion of the inductance from the antenna circuit, by having the switch 15A add some capacity to that circuit, or by making both of these 15A there are shifted, causing that station.

to change to a sending arrangement. At this time. the switches 15 and 15A at station 4 may be in the position for receiving; but, even if they are, the radiations sent out at station 5 will not affect the receiver 16 at station 4; because the antenna 14 at station 4 is tuned to a wave length which differs from the wave length used at station 5 for sending. It is possible, however, to make a systcmusing the same wave length at all times. One way of doing this is by delaying the movement of the switches 15 and 15A, to the illustrated positions, so long that station 5 will have finished sending before station 4 has been changed to receiving arrangement. This has been indicated in Fig. 2 by showing 33 and 34 as slow acting magnets. During this time, any suitable means may be caused to demagnetize the wire 17 at station 4 to thereby prepare it for the reception of further messages.

At the final station, the wire 17 must travel more slowly, when delivering the mes sage, than when receiving it. The message is rendered audible when delivered at the final station by any suitableftranslating de vice; for example, a telephone in the output circuit ofthe tube 23. This change inthe speed of the wire 1.7 may be accomplished in any desired way. As an illustration, I have shown a magnet 36 energized by the same circuit as the magnets 33 and 34. This magnet 36 may shift any desired speed-changing mechanism.

Obviously, any apparatus capable of simultaneously sending and receiving could be used instead of that illustrated. The changes needed to make use of such apparatus would consist almost entirely in the omission of certain parts. Accordingly, it is deemed unnecessary specifically to illustrate such a system.

As illustrated in Figure 4, the system may be applied to a plurality of chains of stations. For example, a central station 41 may be connected by a chain of stations 42 to an end station 43, by a chain of stations 44 to an end station 45, by a chain of stations 46 to an end station 47, and by a chain of stations 48 to an end station 49. Each of the end stations has assigned to it a particu lar wave length for sending and receiving or a particular pair of wave lengths, one for sending and one for receiving. The central station 41. is provided with a plurality of sets of apparatus like that illustrated in Fig. 2. Each set is made adjustable so that its sending and receiving arrangements may be tuned to correspond to any of the end stations.

In this arrangement, assuming that station 45 desires to deliver a message to station49, a call is first sent from station 45 to the central station. The call is sent in the way already described and travels along the chain 44 to the central station 41. It is received there by apparatus so broadly tuned that calls over any of the chains can affect it. In response, the operator tunes the receiving device of one of the sets of apparatus at station 41 to the 400 meter wave length in order that this set may receive the message from station 45. The call itself, or a special code after it, informs the operator that the message is intended for station 49. He, therefore, tunes the sending part of the same set oi apparatus to 700 meters. The code signal just mentioned travels along the chain 44 and is received either on the broadly tuned device or on the set oi apparatus the operator had just tuned. The message itself then travels along the chain 44 in the way already described. At theend of the message, the automatic shift of this set of apparatus at station 41 to sending CO11ilt1011,-Ct1ll:t5 the message to be transmitted at a frequency to which stations in chain 48 are tuned. It, therefore, travels to station 49.

In the same way, any two end stations may be put into commimication, or the central station 41' may itself act as an end station. It will be obvious that the number of sets of apparatus at station 41 need not be as great as the number of end stations. It is suil icient if the apparatus at the central station is able to take care of the maximum number of simultaneous messages that the operators desire to send.

Numerous modifications using the principles of this invention will be apparent to those skilled in the art. The fact that one specific showing of one modification is necessary in order to clearly explain the invention is not to be taken as any indication of: an intention to limit the invention to such specific application, but it is intended that the invention be limited only by the prior art or as indicated in the following claims.

hat I claim is:

1. In a signal relaying station, a communication circuit, a receiving device, a sending device. means for bringing one or the other of said devices into operative relation with the communication circuit, means responsive to predetermined signals for actuating said first named means, whereby arrival of said predetermined signals will first start the station to sending and repetition of said predetermined signals will prepare the station for receiving.

2. In a signal relaying station, a record carrying material; means, active in one condition of the station, for registering signals upon said material; means, active in a. second condition ofthe station, cooperating with said material, for transmitting signals; means for alternately changing the station from registering to transmitting or the reverse, said changing means being actuated upon the registration or transmission of certain predetermined signals, whereby sending said predetermined signals atthe end of a recorded mes age will'cause the station to transmit the whole of said message and said predetermined signals and return to regisstations, one for each chain, means at each end station for sending signals of a character characteristic of that station, means at each relay station adapted to receive and transmit signals of only the character helonging to the end station for the-chain in which said relay station is, and coupling means at the central station for receiving signals characteristic of one chain and trans mitting corresponding signals characteristic of another chain.

5. 'In a signalling system, a plurality of chains of relay stations, a central station common to said chains, a plurality of end stations, one for each chain, means at each end station for sending signals of a character characteristic of that station, means at each relay station adapted to receive andtransmit signals of only the character he loijiging to the end station for the chain in which said relay station is, and adjustable coupling means at the central station for receivi g, signals characteristic of one chain and transmitting corresponding signals characteristic of another chain, said coupling means being fewer than said chains andwhich consists in sending a message to the station, recording it there, sending changeover impulses at the end of said message, recording them at said station, changing the station from receiving to sending hy-the action of said change-over impulses, sending the recorded matter from said station and changing the station from sending to receiving by the action of the recordedchange-over impulses, and repeating these steps throughout a chain of stations, and translating the record at the final station.

In testimony whereof I afiix my signature,

BRUNO ROSENBAUM. 

